Online Course Discussion Forum

Math Challenge I-A Spring 2019 Week 5

 
 
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Math Challenge I-A Spring 2019 Week 5
by Amy T - Saturday, 30 March 2019, 6:58 PM
 

The number 2424 has the property that it is divisible by its lead digit. How many whole numbers (strictly) between 2020 and 6060 have this property?



What does it mean?

 
Picture of Amy T
回复: Math Challenge I-A Spring 2019 Week 5
by Amy T - Sunday, 31 March 2019, 7:11 PM
 

never mind

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Re: Math Challenge I-A Spring 2019 Week 5
by David Reynoso - Monday, 1 April 2019, 10:41 AM
 

Just in case you still need some help with this problem: The leading digit is the first digit on the left, so you want to find how many numbers between $20$ and $60$ are divisible by their tens digits.